2D finite element simulation of tube hydroforming process

Abstract : Tube hydroforming is receiving the greatest attention especially in the automotive industry. The advantages of this process when compared to traditional manufacturing methods are considerable including savings, weight reduction, quality improvement and accuracy. An internal pressure inside the tubes achieves the forming. Axial forces can also be applied simultaneously to optimise material flow during expansion. The finite element analysis could help to determine the optimum parameters for this forming process. In this work, axisymmetric numerical simulation is presented. The numerical model is based on implicit formulation of mechanical equilibrium The elastoviscoplastic constitutive equation includes work hardening and strain rate effects. The hydroforming of a tube is limited by the occurrence of necking. The forming limit diagram is very helpful to evaluate the margin with respect to the limit pressure and to optimise the global pressure cycle.